2003 Sundancer 240 5.0 mpi Alternator? - Last weekend I took one of my batteries out to change it and went on a 1 hour ride with one battery. My radio did not work so on the way back (another hour) I put the battery selector to both so it powered the radio. When I returned to dock I smelt some burning rubber in engine compartment. I installed a new battery and went out yesterday. The volt meter stayed at 13 (usually runs at 15 or 16). The temp gauge showed 140 when it usually shows 170. I then got a long beep while getting up on plane. SmartCraft threw a few codes (fuel gauge, trim gauge ) I switched to other battery and did not get the beep or any other codes. While anchored, I switched back to other battery and it did die after a few hours of radio, water pump, etc. no issues on way back with good battery (other than volt meter showing 12.5 volts. Did I burn out my alternator? How can I test it? Thanks
Did I fry my Alternator?
- Thread starter Erick
- Start date
- Mar 8, 2012
- 225
- Boat Info
- 350 Sundancer Coupe 2020
Prior
310 Sundancer 2015
- Engines
- Dual Horizon 8.2 V Drive
Easiest way is to make sure the motors are isolated from one and other electrically. Then check the voltage at the battery before starting. Once started test the voltage again. If the alternator is working the voltage will be 13 or low 14 volts. Make sure any battery charger (on the AC panel) you have is off.
Skybolt
Well-Known Member
- Nov 11, 2014
- 6,483
- Boat Info
- Reel Nauti
460 EC
- Engines
- Detroit 6v92TA
(Low profile's)
Alison Gears
Westerbeke
12.5kw Genset
You should never run the engine if the alternator is not connected to a battery.
It was connected to 1 battery but the battery selector was on both, even though there was only 1 battery. Doing this energized my radio. Wish I didn't do it now.
- Mar 8, 2012
- 225
- Boat Info
- 350 Sundancer Coupe 2020
Prior
310 Sundancer 2015
- Engines
- Dual Horizon 8.2 V Drive
It’s how we all learn, I’m not sure of your switch but I believe that when you go from one battery to another on the switch it cuts both for a moment and that may have fried your diodes in the alternator.
Just checked with a voltmeter - there is voltage when running on the alternator orange line but only 11.5 volts. Also voltage at the battery is 11.5 when running, 12.5 when not running. Going to order an alternator.
blaster
Well-Known Member
- May 23, 2011
- 3,471
- Boat Info
- 2010 sea ray 205 sport
F-250 CCLB 6.2 4x4 3.73 rear.
- Engines
- Mercruiser 4.3 mpi alpha 1.62
Order a new battery switch with an alternator field disconnect.